This invention relates to a sight head equipping an aircraft such as a rotorcraft. More precisely, the object of the invention is a sight head fitted with an integrated laser designator for the illumination of a target using a laser beam radiating in the visible or near infra-red spectrum.
The invention applies in particular to a sight head of a helicopter weapon fire control system.
It is known to fit military helicopters with a weapon fire control system equipped with a sight head. More precisely, the sight head comprises a pod the major part of which is generally located above the roof of the helicopter fuselage. An eyepiece carrier arm extends the sight head to the inside of the fuselage.
Under certain conditions of use, it is necessary to illuminate the target with a laser beam. Depending on whether the operator observes the target with his naked eye or using night vision goggles, a laser beam transmitting in the visible or near infrared spectrum is used.
Currently, the illumination of the target is performed using a device known as a xe2x80x98laser designatorxe2x80x99. More precisely, this device is hand held outside the helicopter. In effect, the fuselage of the helicopter creates a strong attenuation of the laser frequencies and would cause harmful internal reflections if the laser pointer were to be used inside the helicopter.
Because of their manual characteristics and the need for deployment outside the helicopter, the existing laser designators do not allow precise sighting. The usability is thus reduced.
FR-A-2 640 037 relates to a sight mast for a helicopter fitted with a telemeter or laser photoelectric shutter which looks through the blades of the rotor. This arrangement allows the motion of the blade during the alignment phase between the sight and the seeker head of a missile to be taken into account.
Precisely, the object of the invention is a sight head equipped with an integrated laser designator to allow an optical pointing accuracy and an optimum usability, without degrading the inherent characteristics of the sight head.
More precisely, the invention refers to a sight head for a rotorcraft, comprising a pod in which at least a part is available mounted externally to the rotorcraft fuselage, characterized by the integration of a laser designator in the said part of the pod.
Preferably, the part of the pod installed externally to the fuselage has the sight head covered by an existing aerodynamic fairing. Thus, the aerodynamic characteristics of the sight head are not modified by the installation of the laser designator.
Advantageously, the laser designator comprises a laser transmitter and a means of adjusting its alignment within the said pod, allowing the laser beam from the laser designator to be aligned parallel to a sight axis of the sight head. It is thus possible to accurately adjust the parallelism of the laser beam with the axis of the sight head.
In this case, the preferred alignment method consists of three adjustment screws equally spaced around the laser transmitter.
Furthermore, the laser designator also comprises its own power supply for the laser transmitter and a radio receiver, required to start and stop the laser emission.